Today my harddrive had some kind of mid-life crisis and got itself in a state that no amount of dskchking or "Startup Recovery"ing could resolve, so I attached another disk, installed windows on that and recovered the files from the old disk, all well and good.

The problem is there's one directory I had encrypted, and of course the contents of the recovered files are gibberish. Is it possible, since I have full access to the disk, and know the account password it was encrypted with, I may still be able to decrypt it somehow?

Edit: I do not have explicit backups of the keys, I am hoping that Windows stores them somewhere by default.

In the end I used http://www.diskinternals.com/efs-recovery/ which was quick and painless: found the encrypted files/authentication data with a scan of the drive, requested password for the account, and decrypted the files.

I was even able to use the free version as it allows preview, and the files I was recovering were plain-text.